I recently made a post about my FreeSync certified monitor not supporting VRR over HDMI. I thought that there was VRR support over HDMI even for versions below 2.1 spec. Am I mistaken in my assumption¿? Has the HDMI forum prevented the implementation of FreeSync in the open source drivers¿?
Obligatory fuck the HDMI forum and the HDMI spec.
TL;DR depends on your gpu.
Some monitors below HDMI 2.1 support the early version of freesync made by AMD, while others support a fragment of what became 2.1’s VRR. The former is supported only by AMD, while the latter by both AMD and Nvidia (Pascal and upper with latest drivers). If you have the former, the monitor is probably not compatible with DP’s official adaptive sync, so Nvidia won’t work even on DP.
But… Even if you have AMD, due to a bug in the driver, if you have a Polaris GPU it might not detect the vrr capability over HDMI (but will over DP). I know for sure that RDNA 2.5 cards support it, in theory it should work even for all Vega and Navi GPUs, but I haven’t tested it.